Skylights are window units that transmit light through an opening in a building roof, and have long been used to produce aesthetic lighting effects in residential and commercial building construction. Typically, a frame structure is utilized to support the light-transmitting central portion and weathertightly-seal the assembly to the supporting roof structure. Preferably, skylight assemblies are easily assemblable on-site, because of the complexity of installing such assemblies on pitched roof surfaces.
It is known to provide a pre-assembled, welded skylight frame installed as a unitary body. This type of skylight frame suffers from the drawback of bulkiness, which hinders efficient installation. Another type of known skylight frame assembly utilizes separate frame members joined together at the corners on-site. This second type of prior skylight frame assembly has tended to be difficult to install, requiring tools and a relatively high degree of skill and experience on the part of the installer.
Thus, there presently exists a need for a skylight frame assembly that is assemblable on-site from separate members, but which has a corner assembly which is efficiently assembled and yields adequate structural and sealing characteristics.